The Gut Biome and Sport Performance

Tanya Jones Digestive Health, Food for Runners Leave a Comment

After my last post on nourishing performance, click HERE for a recap, I was really motivated to learn more on managing my gut biome and how that specifically can help my sport performance. During my research I discovered some very interesting things. Did you know that your gut contains more than 100 trillion microorganisms, including bacteria, viruses, and fungi? That’s an incredible internal community that we host, I mean it’s also a bit creepy but mostly fascinating. This microbiome plays a critical role in your health and performance. All these organisms perform essential functions that include setting our metabolism, neutralizing drugs and carcinogens, synthesizing vitamins (like vitamin K), maintaining our intestinal lining, contributing to mood, synthesizing short chain fatty acids (signaling compounds), and so much more. They can send signals across our entire body that support immunity, protect us from foreign invaders, and regulate oxidative stress. There is a direct link between what’s happening in the gut and what all of our systems actually can do and how we can actually perform.

In my last post I also discussed including a variety of foods into your diet to ensure a variety of nutrients but also to support a diverse gut microbiome. A diverse gut biome is a marker of a healthy gut. The types of bacteria that are actually in our gut can dictate what’s happening from a central nervous system response (how we respond to stimuli), an autonomic nervous system response (regulation of heart rate, blood pressure, respiration, digestion, etc.), what’s happening with our immune system, and how our gastrointestinal tract functions. The challenge we face today is maintaining that biodiversity due to intake of too much processed foods, lack of exercise, and increased stress levels. Studies have also shown that population of your gut biome can impact your response to glucose, either generating a blood sugar spike or maintaining an even level. As we know, with endurance sport and especially women on their menopause journey, the ability to process glucose at a consistent rate during exercise and at rest is critical to performance and body composition. If we have a misstep in the type of bacteria that we have, then we end up with a greater risk factor for metabolic disease, cardiovascular disease, obesity, increased stress responses, anxiety, and depression.

When you are doing regular moderate exercise, you increase the diversity of the bacteria. This is because you are reducing the oxygen and increasing the heat that goes to the gut and creating an environment that allows some bacteria to grow and stunts the growth of others. Then, with the addition of certain foods during and right after exercising, you can encourage the growth of bacteria that you want. This is why it is important to take some time and care when planning your nutrition for during and after exercise. Knowing that you can actually influence the population that survives under exercise stress, it would make sense to consume good quality, whole foods that will drive the growth of beneficial bacteria that are strong under stress. If you consume more processed foods, you are likely driving your gut population towards pathogenic bacteria that thrive under stress. The potential outcome of this is impairment of your ability to absorb nutrients and manage blood sugar, while also contributing to a body composition changes towards higher body fat than lean muscle. Also, when under exercise stress, your intestinal mucosal lining is a bit eroded from the heat and hypoxia, which can result in intestinal distress and potential leaky gut. By providing the correct nourishment for them to thrive, you’re going to stimulate the bacteria that are going to try to keep those junctions tight. Now that we know what can happen to our gut biome during exercise and that we have the ability to control the population by supporting the growth of beneficial bacteria, you will also want to consider looking at a progressive periodized training program as well as matching your nutrition with each training situation. The goal is to utilize all the positive influences that exercise and nutrition have on our bacteria.

As a lot of us are endurance athletes, we do need to be careful that we don’t create a situation, with regards to the nutrition and adequate recovery, that will create havoc for our gut though. We know that extreme exercise increases inflammation in our muscles, joints, and digestive system. This inflammation can directly influence the bacteria, and that can result in a gut biome that keeps contributing to this inflammation. We know that there are some beneficial bacteria that survive extreme exercise, but pathogenic microorganisms are much better suited for this environment. These microorganisms produce metabolites that impact your intestinal lining, create inflammation, and increase your overall stress load. The same goes with the use of highly processed, simple carbohydrates during the ultra and other types of training. We usually end up eating a lot of these simple carbohydrates to fuel these activities and this will stimulate the growth of the bacteria that thrive on them. Then when you’re not exercising, you can have an overgrowth of that bacteria that tip you into a gut biome population that will stimulate you to crave more simple sugars, alter your mood and promote a higher body fat composition.

There is also a connection between your gut microbiome and your mitochondria (the energy powerhouse of your cells). This is super important for athletes looking to get the best out of their bodies. Your microbiome and mitochondria can “talk” to each other using cellular signaling molecules such as short chain fatty acids called butyrate. These molecules also go on to be precursors to a lot of our hormones and other responses that happen within the body. A healthy gut produces large amounts of butyrate but athletes who consume large amounts of simple sugars, processed foods, or pro-inflammatory omega-6 fats might be compromising this process. It’s not just the communication from your gut microbiome to your mitochondria that is important, your mitochondria also talk to your immune system. Your mitochondria actually keep an eye out for potential foreign invaders, signs of cellular damage, and then relay that information to your immune system. Our mitochondria also support diversity in our gut biome by maintaining the protective mucus lining of our intestinal system which we now know can be impacted by exercise. Other factors that impact the integrity of our gut lining are high sugar diets, processed foods, NSAIDS, antibiotics, and chronic stress.

A healthy gut biome also produces another short chain fatty acid called propionate. This also supports the integrity of your intestinal lining, limiting permeability, and promotes the down regulation of pro-inflammation in your gut cells. Maintaining a healthy intestinal lining, reduces leaky gut which triggers your immune system. If you are struggling with a leaky gut, your will likely feel systemic inflammation as sore muscles and joints, notice that you are more reactive to certain foods, take longer to recover from your activities and find that you are sick more often as your immune system is fatigued and unable to mount a defence. Chronic gut inflammation also creates an environment that promotes the growth of pathogenic bacteria, yeasts and viruses that increase gut dysfunction, increase systemic inflammation, and limit your ability to absorb the nutrition you need to fuel your active body.

Another important aspect to consider is that our gut microbiome can also affect our sleep. If we have a greater number of bacteria that stimulates our sympathetic nervous system, then we have poor quality sleep. With poor sleep, we spend less time in short-wave restorative sleep and we end up with less REM sleep. For both athletes and non-athletes, sleep is essential for overall health and wellbeing. Restorative sleep allows your heart to rest and for cell and tissue repair. During sleep, your body also produces cytokines, which are hormones that help the immune system fight off infections. All of these restorative effects are important for an athletes’ recovery and performance. When you are sleeping, your memories are also consolidated, so when athletes practice or learn new skills, sleep helps form memories, and contributes to improved performance in the future. Sleep is also essential for cognitive processing, and lack of sleep can have adverse effects on decision making and adapting to new situations. Quality sleep is associated with improving overall mood therefore sleep can prevent irritability and decreases the risk of developments such as depression.

So, when we start looking at what are we doing with extreme exercise, knowing that there’s a higher risk for disrupting our gut microbiome, we need to really think about what we are eating during and around training and what are we using for fuel for those long training sessions. We can also look at how we are using exercise and complementary nutrition to improve the gut. The goal is to reduce total body inflammation which aids in absorption of nutrition to fuel our active bodies, less pressure on our immune system, so we stay healthy, and have a quick and acute immune response when appropriate. We do want to a little bit of inflammation that occurs during exercise, so that we can increase the biome population and the metabolites to quickly overcome it. This leads to gut lining support, an increase our anti-inflammatory responses, an increase in our antioxidation capacity, reduced fatigue and reduced delayed onset muscle soreness (DOMS).

We know that there’s a decrease in the oxidative stress, decreased inflammation, and better gut health with the focus on plant-based diets. I don’t mean to say that you need to be only plant based, the goal is to increase your plant diversity.  A wide diversity of plant foods enhances the diversity of that bacteria in the upper and lower gut as we discussed in my last nourishing performance post, click HERE for a recap.  This has a positive influence on mood, enhances parasympathetic activity, and supports our immune system. With the amount of chronic stress we face, as well as exercise induced stress, we want to have something that decreases sympathetic and increases the parasympathetic system (rest and digest). Plant based diets have been shown to improve blood lipid profiles, support weight loss and reduces body fat gain. There is also a reduction in cardiovascular disease, and it helps with metabolic control. One of the biggest outcomes of following a plant-based diet for is it effectiveness in blood sugar control and reducing oxidative stress in peri and postmenopausal women. This is primarily due to the wide variety of plant matter, coming into the gut microbiome and supporting microbiome diversity.

Here is a gut loving recipe that has fiber, pre and probiotics, zinc and anti-inflammatory foods. Lentils are fiber-rich and increase the production of short chain fatty acids that promote the growth of good bacteria and support intestinal lining health. Probiotics found in fermented foods like kimchi are live bacteria that can help stabilize the intestinal lining, fight off bad bacteria, and reduce inflammation. Prebiotics like garlic support digestive health by feeding the good bacteria. Sesame seeds contain zinc which is essential for cell survival and function and maintains the gut membrane integrity. And finally, carrots are packed with vitamin A, which is a powerful antioxidant that helps reduce oxidative stress and helps manage inflammation.

Korean Jackfruit Bowls (4 servings)

  • 1 cup Brown Rice (dry, uncooked)
  • 2 1/3 cups Canned Jackfruit (young, drained and rinsed)
  • 1 1/3 Garlic (clove, minced)
  • 2 Tbsp Tamari
  • 1 1/3 tsp Coconut Sugar
  • 1/3 tsp Red Pepper Flakes
  • 1/3 Lime (juiced)
  • 1 1/3 tsp Sesame Oil
  • 1 1/3 Cucumber (diced)
  • 2 2/3 Carrot (medium, grated or diced)
  • 2/3 cup Kimchi
  • 1 1/3 Tbsp Sesame Seeds
  • 1 1/3 stalks Green Onion (diced)

1. Cook rice according to the directions on the package and set aside.

2. In a pan over medium heat, add the jackfruit, garlic, tamari, coconut sugar, red pepper flakes and lime juice. Stir until well combined and use a wooden spatula to break up and shred the jackfruit. Cook for 15 minutes, or until the jackfruit is soft. Once it is done, add the sesame oil and remove from heat.

3. Plate the rice, and add the cucumber, carrots, kimchi and jackfruit. Top with sesame seeds and diced green onion.


It is believed that diet play the biggest role in gut microbiome diversity but there are other strategies to support your digestion to make sure you are absorbing your nutrition to get the best performance you can.

Here are 8 diet and lifestyle habits to help improve your digestion.

1. Thoroughly chew your food.

The goal is to break your food down into individual components such as amino acids, short chain fatty acids, glucose molecules, minerals and vitamins. Chewing your food well helps prep it for chemical breakdown by gastric juices and enzymes. As you recall, when you’re under chronic stress or have initiated a sympathetic nervous system response, digestion is not the priority so, any way that you can support your system and make the process easier is a good idea.

2. Avoid cold water with meals.

Drinking too much water, especially ice-cold water, dilutes the digestive enzymes and slows down the digestive process.

3. Manage your stress.

It’s unlikely to avoid all stress, exercise in itself is stressful, but it is a stress that we are looking to make adaptations from. The goal here is to limit stress where you can and to support your body to manage the stress that you have. One thing you can control is to keep your surroundings calm when eating. This is where you want to do your best to avoid rushing and eating on the run, take a moment to sit down to eat while avoiding screen time to be mindful of your food.

4. Add probiotics and fermented foods.

There are many reasons a digestive system becomes unbalanced. These include illness, taking antibiotics, a poor diet, or an overgrowth of bad bacteria. Probiotics help to keep the digestive system in balance. A healthy and diverse gut biome helps to keep you healthy by supporting your intestinal integrity, immune function and controlling inflammation. Enjoy some kimchi, sauerkraut, miso, kefir, yogurt and kombucha.

5. Add prebiotics.

Prebiotics are very fibrous foods that are hard for your body to digest so they can travel to your lower digestive tract and are food for your gut’s healthy bacteria. As much consideration needs to go into feeding your good bacteria as goes into feeding your body for sport and performance. Add some apples, asparagus, onions, garlic, chicory, dandelion greens, and bananas to your meals.

6. Identify food intolerances and allergies.

Food sensitivities can contribute to systemic inflammation, muscle and join pain, a reduction in the ability of your body to absorb the nutrition you are taking in, and limit your ability to recover from exercise.

7. Stay active.

There is a case for taking that post meal walk. A little bit of movement helps move food through your digestive system. Aerobic exercise also increases the number of mitochondria you have, and we know that mitochondria support gut biodiversity, support your immune system, while also increasing your available energy.

8. Limit intake of processed foods.

Consuming too much highly processed foods and other unhealthy foods can harm your gut microbiome. This type of diet promotes the growth of pathogenic bacteria, over beneficial bacteria. While we often use processed food during activity, the goal is to limit it’s use to during activity and eat a whole food and diverse diet the rest of the time.

I feel like we have learned a lot here and have a decent framework to go forward, to take care of our internal community, and to achieve those performance goals that we are after. Finally, I would like you to ask not what your gut biome can do for you but what you can do for your gut biome.

Train well and empower yourself.

Tanya R.H.N

Sports Holistic Nutritionist

Strength and Conditioning Coach

Multisport Coach

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